Association of Iron Overload with Insulin Resistance in Transfusion-Dependent Beta Thalassemia Major Patients via Homeostatic Beta-Cell Model (HOMA-Beta) and Homeostatic Insulin Resistance Model (HOMA-IR): Insights from a Thalassemia Center in Karachi, Pakistan

Abstract

Objective: To determine incidence of diabetes mellitus in transfusion dependent beta-thalassemia major patients, pancreatic beta-cell function by HOMA-beta & insulin resistance by HOMA-IR in beta-thalassemia major patients and the relation of beta-cell function and insulin resistance with iron overload in transfusion dependent beta-thalassemia major patients.

Methodology: This cross-sectional study was conducted in Baqai Medical University Karachi and Muhammadi Thalassemia Center Karachi. A total of 100 patients of both genders; age group between 2 years to 16 years were included in this study. Lab investigations were performed for FBS, Plasma Insulin, HbA1c, and Serum Ferritin on fully automated chemiluminence analyzer. HOMA-IR and HOMA-Beta were calculated.

Results: Prevalence of diabetes mellitus in transfusion dependent beta-thalassemia major patients was 15%. According to HOMA-IR, 48% patients had severe insulin resistance. HOMA-Beta was significantly lower in diabetic than non-diabetic patients. Relationship between HOMA-IR and HOMA-Beta according to iron overload status (? 2500 and >2500) was positive but the correlation was strong (r=0.85) between HOMA-IR and HOMA-Beta in patients whose iron overload status was less than and equal to 2500 however correlation of these HOMA-IR and HOMA-Beta was week (r=0.209) in those whose iron overload was >2500.

Conclusion: Iron overload is significantly promoting insulin resistance in transfusion-dependent beta-thalassemia major patients. Beta-thalassemia major patients are developing insulin resistance because of repeated blood transfusions. HOMA-Beta and HOMA-IR are reliable predictors of insulin resistance.